Maintaining Equipment Stored in Africa

By Ned Stearns, AA7A

I joined the VooDoo Contest Group for the November 2005 CQWW DX CW contest activity in Bamako, Mali. I had been involved in some of the initial planning for first African DXpedition trip by this group in 1994 but demands of the family and my work prevented me from participating with this group until 2005. Despite being a seasoned contester and DXer, I was rookie on this team of renowned operators and happily accepted the off-peak assignments in the Multi-multi operation. The station design in this 2005 operation was fairly straightforward with an HF transceiver and an Alpha amplifier on all six HF bands plus a separate, versatile full power multiplier station. Each station had its own mono-band antenna that one would be happy to have at their home station. With seven active positions, a team of ten operators as we had in 2005 easily kept the contesting at optimum effort for the full 48 hours.

The ensemble of equipment that had been assembled by this unique contest team was quite impressive to this rookie. One of the most interesting aspects of the group’s equipment was the large collection of Alpha amplifiers, models 76CA (quantity of five) and 78 (quantity of two).

Voodoo Alphas

I was a little familiar with Alpha amplifiers having been in the hobby for nearly 40 years. I had never felt compelled to invest in one for my station and was in awe that this operation had seven amplifiers in the equipment pile. These amplifiers all were equipped with three 8874’s and hypersil transformers. The amplifiers were all purchased in hamfests over the years by the VooDudes and hauled into West Africa as checked baggage. Most of them were quite experienced before they ever made it to this part of the world.

The VooDoo Contest Group practice is to locate the contest station at a high-end (Africa scale) hotel and occupy the top floors near the roof to minimize coax runs. So, one of the first things that happens in a station deployment is the hoisting of gear from ground level where it is deposited by ground transportation up to the top floors of hotels. When I joined the group, the amplifiers were still mostly packed in original cardboard boxes that had seen many years of deterioration in the West African environment. One or two of the amplifiers had managed to be stored in a Pelican case, but it was the exception. The transformers all were packed in old hat boxes and aluminum cases.

When setting up the Multi-Multi station for seven positions, all seven Alpha amplifiers must work. Upon arriving in West Africa and unpacking the gear after a year of storage in high humidity and possibly some recent arduous transportation over unpaved African roads, sometimes the amplifiers don’t come up working. In 2005, we were fortunate to have no issues with the equipment. As an electrical engineer with considerable RF experience, I inherited the responsibility on the team of maintaining the radios and amplifiers for the stations and sorting out RF issues in the multi-transmitter setup. I mostly spent my time in preparing for this contest by replacing bad cables and trying to make sense of the various coaxial traps that had been cut and pressed into service by my RF-savvy predecessors. We managed to do well in my first year on the team and I went home with a few ideas of improvements to make in the station in our next outing in a year’s time.

As time went on, we started to experience some problems in the amplifiers either during initial setup, when there was time to implement some repairs, or during contest operation, where we would conduct rapid reconfiguration of the stations. In the ensuing years, we never had seven fully operational amplifiers by the time the contest started. Then began a new station configuration where we would not field 6 run stations plus a multiplier station. The team adapted to an approach where we would set up four or five run stations plus a multiplier station where two of the stations would alternate between a low frequency band and a higher band conducting a switchover at sunrise and sunset. This gave us at least one and maybe two hot spare amplifiers (and possibly radios) that we could quickly press into service in the event of a failure. Even in the best years propagation-wise, the low frequency run stations were dormant (or manned by rookies) during the daytime hours and we lost little effectiveness in the process of changing to this configuration. It would be the function of the Multiplier station to check for long path openings on 10 and 15 during the night to not miss those critical openings for big scores in West Africa.

In the two years that the team operated in Sierra Leone (2009 and 2010) and the first year in Liberia in 2011, the mountain of VooDoo contest hardware was not available to the team. All of our contest gear was caught up in a civil disorder situation in Guinea during those years and all of our contest efforts were managed using equipment that the operators hauled with them in the checked and hand-carried baggage. The team conducted only Multi-single or Multi-Two contest operations in those years due to the limited equipment available. In 2012, we solved the logistic problem of moving the VooDoo Contest Group’s hardware into Liberia prior to the contest. It had all been in storage in totally unknown uncontrolled environments for almost four years. Going in to the effort in 2012, we were faced with a lot of uncertainty as to the operating condition of the hardware…mostly that of the set of seven Alpha amplifiers. As we were contemplating the options of operating as Multi-Two or Multi-Multi modes, we were totally uncertain whether we could assemble three, four or even five station with the equipment possibly having deteriorated into an unusable state. Since 2012 was going to be our last hurrah in West Africa, we elected to go for M/M operation and set up as many stations as possible giving the team to all maximize their time on the air.

Upon arriving in Liberia in 2012, I went immediately to work to perform my usual ritual of assembling the Alpha amplifiers, conducting my usual battery of tests and then turning them over to the other ops to use in pileup operations that we usually conduct in the days prior to contest operations. I normally set up a work bench in the contest area to work on the amplifiers that is well lit and provides access to all sides of the amplifier at once.

Alpha under repair

Initial inspection of the amplifiers after the long storage seemed good. I got four amplifiers up and running in a couple of days. I had to do some surgery in some of the amplifiers to bypass some elements in the amplifiers, such as bulkhead coax connectors and the internal wattmeters that had completely corroded resulting in significant faults (e.g. no RF output). I had a few days left to get one working amplifier from the three remaining, which seemed like a reasonable objective. However, after a few hours of pileup operations, we were soon down to only two working amplifiers. For the remaining time (even to within an hour of the start of the 2012 contest event) I was working on these amplifiers. And only after rewiring the control circuitry in an Alpha 78 amplifier to match that of an Alpha 76 configuration from memory (since all of the amplifier manuals had turned into paper paste due to a water leak in the case containing all of our equipment manuals) did we finally have the minimum necessary number of amplifiers to support the four station approach we had adopted for this year’s M/M operation. We had no working watt-meters on any amplifier, no indicated high voltage on most amplifiers and marginal keying reliability on one of the amplifiers. But the team was cautious with this equipment and we experienced no additional failures during the contest producing spectacular result for this effort.

My memory of the 2012 contest operation is warmed by the success of reviving as many amplifiers as were necessary to activate EL2A during the contest in the usual VooDoo Contest Group’s way. We always try to be as loud as we can on the bands to maintain our run frequencies and promote low error rates and this year was no exception.

At the conclusion of the 2012 operation we were faced with a new situation. We had some decisions to make about what to do with all of the usable hardware in the contest pile. We debated our options and the weighed the prospects of the added costs of extra baggage fees against the value of bringing a tired amp out of the jungles of Africa. Our final decision was to haul out four Alpha amplifiers (one to the UK and three to the states), leave one working amplifier for the Liberian Amateur Radio Association and to “part out” the remaining two amplifiers with the high valued components. I had a particularly odd sensation as I was hacksawing apart a bracket on a near-perfect Alpha 78. When I got all done removing all of the valuable parts of the two Alpha 78 amplifiers, I was preparing to haul the chassis which had been stripped clean down to the hotel garbage bin. Our good friend Dickson, EL2DT, stopped me from doing this and asked for the two chassis. He had a good friend who could use the metal chassis to make cooking pots for his family. My heart was lifted by the fact that each of these venerable amplifiers would continue to provide service for many years to come.

From Alpha to Cooking Pot